Diagnosing Crohn’s disease can be challenging. (What is Crohn’s disease?) Since there is no single test that can make a definitive diagnosis of Crohn’s, your doctor will typically gather information from several sources. This process may begin with a physical exam and a health history and be followed up with lab tests and scans. Here are some of the most common ways doctors go about diagnosing Crohn’s disease.
The first lab test a doctor may perform might be to collect a stool sample to detect blood in the feces and find out if a protein called calproctectin might be present in the stool. Calprotectin is a major protein found in inflammatory cells and if detected in the sample, may indicate a need for further testing. Stools tests may also be ordered to look for signs of infection. Read more about the calprotectin test.
A blood test may be ordered to see if you have anemia (a condition where there are not enough red blood cells) and to look for signs of infection and inflammation of the intestine.
This test enables your doctor to look inside your colon (large intestine) using a thin, flexible, lighted tube equipped with a tiny camera. A colonoscopy reveals any inflammation or ulcers in the intestine that might be caused by Crohn’s disease. During this procedure, small sample of tissue from the intestine might be taken (called a biopsy) and sent to the lab for analysis to help confirm the diagnosis. VIDEO Learn more about colonoscopies.
Computerized tomography (CT)
You might also have a CT scan, which is a special type of X-ray that provides more detail than a standard X-ray. This test allows your doctor to see the entire bowel (large and small intestines) and the tissues outside the bowel that can't be seen with other tests. This test can help your doctor better understand the location of the inflammation and check for possible complications such as partial blockages, abscesses or fistulas.
Magnetic resonance imaging (MRI)
Instead of a CT scan your doctor may order an MRI, which uses magnetic field and radio waves to create highly defined images of the organs and tissues. The MRI is typically very helpful for diagnosing Crohn’s disease and can produce similar results as the CT scan. The advantage of MRI over the CT scan is that there is no radiation exposure.
If your symptoms point toward the presence of Crohn's disease but other diagnostic tests are negative, your doctor may order a capsule endoscopy. For this test you swallow a capsule that has a tiny camera in it. As the capsule moves through your digestive tract, the camera takes many pictures, which are transmitted to a computer that you wear on your belt. The images are then downloaded to a computer and assessed by your doctor. After the capsule has traveled the length of your digestive system it is easily and painlessly eliminated in your stool.
Double balloon endoscopy
If the capsule endoscopy shows abnormalities in your digestive tract but the diagnosis is still uncertain, a double balloon endoscopy might be performed. This test is similar to the colonoscopy but uses a longer scope that enables your doctor to look further into the small bowel (small intestine) where standard scopes don't reach. A biopsy can also be taken in this procedure if abnormal areas are detected.
Small bowel imaging
This test looks specifically at the small bowel area to help locate areas of narrowing or inflammation that are common with Crohn’s disease. To perform the test you first must drink a solution containing barium. The barium coats the lining of the bowel making it visible on an X-ray or CT scan. Images are taken of the small bowel and analyzed by your doctor.
Though most people will not have all of these tests performed in order to make a correct diagnosis, it may be necessary to have several of them to accurately confirm the presence of Crohn’s or another disorder.
Suggested: Treatments for Crohn's Disease